Atmospheric gas burner with sequential and superminimum device

ABSTRACT

Atmospheric gas burner, for use in oven cooking chambers, and comprising an hollow and prolonged body provided with a first portion able of lodging a main burner and a second portion able of lodging a secondary burner (mini-burner) said two portions being hermetically separated by a wall placed inside said hollow body; on the outer surface of said hollow body a third assembly of cross-lighting ports is placed, wherein said cross-lighting ports extend in correspondence both of said first portion and on said second portion, and preferably are alined each other, a deflecting element is placed outside said hollow prolonged body, which is close and in front of said cross-lighting ports, an is also able of allowing the flame propagation among said cross-lighting holes, and between a fraction of these and said secondary holes. Said deflecting element is placed and extended in such a way not to cover either said main holes and said secondary holes

This invention deals with a gas atmospheric burner with sequentialoperating and superminimum device which can be usable in particular forcooking ovens for domestic and professional use and, at the same time,for defrosting systems on frozen or deep-frozen food. It consists of aknown main burner (1) formed by a Venturi duct (10) and an air-gasmixing chamber (2) supplying the burner by two rows of main ports (3)arranged at 180° laterally and a group of ports (4) arranged at 180°that are used for supplying the mini burner (6) which is the main matterof this invention. Cross-lighting ports (11), placed under thestabilisation deflector (12), specially shown in FIGS. 1 and 3, are usedto transmit the flames automatically from the main burner to the miniburner and they light at the same time the main ports (3) and the groupof ports (4). At the opposite side of main burner inlet there is theinlet for mini burner consisting of a Venturi duct (7) with an air-gasmixing chamber (13) supplying the mini burner which can be of suitabledimensions depending on cap displacement (8). Defrosting flames (Fs)supplied by ports (4) are used to obtain temperatures suitable forfrozen or deep-frozen food defrosting (from 40° to 90°). Main flames(Fp), produced by main ports (3) are instead used for normal foodcooking (from 120° to 300°). The thermocouple (9) positioned at anadequate distance from mini burner controls the presence of the flameand transmit the signal to a control unit operating on the temperaturesystem set by the user.

There are several types of atmospheric gas burners, designed andproduced for oven cooking. But these burners aren't usable fordefrosting systems on frozen or deep-frozen food because they are notequipped with the superminimun device. We know other appliances suitableto defrosting purposes as electric microwave ovens.

However these appliances have two difficulties: they operate by electricpower with high costs and their cooking compartments volumes are verylittle. We remember that the volume of the oven in a domestic range isabout 5 times greater than a standard microwave oven volume. Thereforebenefits with this new invention are evident and for everybody using theoven of cooking ranges.

The purpose of this invention is to cook and defrost by mean of an onlygas burner with sequential system at very low temperatures and this canbe achieved by the particular and specific design allowing to supply twoburners in a perfectly stoichiometric ratio using all kinds of gasmixtures, getting high performances and efficiencies with the samedimensions, with a “range” of temperatures from 40° to 300° and alsokeeping constant the temperatures values that have been set previously.

For a full understanding of features and benefits that could be obtainedby this new gas burner, being itself the object of this invention, thesame burner, just as a non limiting example and in a specific form, isrepresented here in succession and in details according to the followingdrawings where:

FIG. 1 shows a longitudinal and partially sectioned side view of the gasburner according to the invention,

FIG. 2 shows a perspective of a partially sectioned view of the gasburner of FIG. 1,

FIG. 3 shows a view corresponding to the one of FIG. 1, but with a maincomponent of the gas burner disassembled from the main body of it.

In these figures common details and parts are reported with the samereferences.

Basically, the purpose of the atmospheric gas burner with sequentialoperating and superminimum device is to be particularly usable forcooking ovens for household and commercial use; this burner consistsbasically of a main burner (1) with a mixing chamber (2) supplying aVenturi duct (10) by an air-gas combustible mixture which feeds the mainports (3) creating flames (Fp) and cross-lighting holes (11) serving totransmit the flame from the main burner to the mini burner and viceversa.

As illustrated on FIG. 1, the burner group consists of two opposite gasinlets, the former inlet supplying the main burner the latter inletsupplying the little burner or mini burner. The whole assembly is easilyproducible by common machine tools and industrial processing lines.However burner group will be synthetically described for a fullunderstanding of the whole burner assembly and operating. As FIG. 1shows, burner assembly (1) consists of a Venturi duct (10) whoseexternal end, the one with minor diameter, is supplied with a suitableair/gas mixture produced and admitted by an opportune group (2) called“mixing chamber”; anyway its construction and operating, though they arewell-known, will be herein described for clarity. According to fig.1, itis clear that the mixing chamber (2) consists of an injector (not shownhere) installed at its extremity. This injector is arranged in a coaxialway as to the Venturi duct (10) and inside the air-gas mixing chamber.When the injector is supplied with gas, it emits by the outlet hole, inthe direction of Venturi duct (10), a relative gas jet which, as it'swell-known, drags a suitable rate of air called “primary air” and mixeswith the air creating a combustible air-gas mixture: by the oppositeextremity of Venturi duct (10), the extremity having the biggerdiameter, the air-gas mixture pours out supplying the main burnerintended for cooking and cross-lighting holes (11) which, in case ofdefrosting mode, light ports (4) igniting defrosting flames (Fs).

At the opposite extremity of the main burner (1) there is the air-gasmixing chamber (13) where the injector (not shown) is placed at theextremity; the injector let the mixture flow coaxial as regards the duct(7) getting into the chamber of the mini burner and supplying the flamesintended for defrosting (Fs). In FIG. 1 a flame detector device is shown(9); it works by a temperature control system and puts in operation themain burner (1) or the defrosting burner according to the temperatureset by the user, or the two burners together.

FIG. 2 shows a simplified sectional and perspective view of defrostingburner.

In conclusion, this sequential burner, object of our invention, allowsnot only to avoid the above mentioned inconveniences of commondefrosting appliances, but also to get considerable benefits.

In fact this burner allows to get a large range of temperatures insidethe oven varying from 40° to 300°, able to cook every kind of food asvegetables, sweets etc . . . , or to defrost at very low temperaturesvegetables, white meat, etc. . . . To this day this versatility isunavailable in the market. In reality by mean of an only burner and twogas inlets we can get either cooking mode or defrosting mode.

Of course different changes could be introduced to this burner, objectof our invention, without leaving this described domain and, accordingto enclosed drawings, the following claims and then the domain of ourprivate industrial patent.

1. Atmospheric gas burner, particularly for the use in the cookingchambers of household or commercial (catering) cooking ovens, andcomprising at least an hollow and prolonged body, characterized in tothat said hollow prolonged body comprises a first portion able oflodging a main burner (1) and a second portion able of lodging asecondary burner (mini-burner) (6), said two portions being hermeticallyseparated by a wall (8) placed inside said hollow body.
 2. Atmosphericgas burner according to claim 1, characterized in that on the outersurface of said hollow body a first assembly with main holes (3),associated to said first portion, said main holes being able of allowingthe emission of respective gas jets related to said main burner (1), anda second assembly with secondary holes (4), associated to said secondportion, said secondary holes being able of allowing the emission ofrespective gas jets related to said secondary burner (6), are placed. 3.Atmospheric gas burner according to claim 1, characterized in that saidmain and secondary burners (1, 6) are associated, on their oppositesides of said hollow prolonged body, to two respective mixing chambers(2, 13) able of supply with two respective gas flows, respective Venturiducts (10, 7), which penetrate into said respectively main burner (1)and said secondary burner (6).
 4. Atmospheric gas burner according toclaim 3, characterized in that said Venturi duct (7), associated to saidsecondary burner (6), is implemented through a conduit which issubstantially outside of said hollow prolonged body.
 5. Atmospheric gasburner according claim 2, characterized in that: said main holes (3) areplaced successively along two straight lines which stretch parallel eachother on two opposite sides of said first portion, said secondary holes(4) are placed successively along two straight lines which stretchparallel each other on two opposite sides of said second portion. 6.Atmospheric burner according to claim 1, characterized in that on theouter surface of said hollow body a third assembly of cross-lightingports (11) is placed, said cross-lighting ports extend in correspondenceboth of said first portion and on said second portion, and preferablyare lined each other, a deflecting element (12) is placed outside saidhollow prolonged body, and which is close and in front of saidcross-lighting ports, a gap is implemented between said deflectingelement and the surface of said prolonged hollow body, whose thicknessis able of allowing the flame propagation among said cross-lightingholes, and between a fraction of these and said secondary holes (4). 7.Atmospheric burner according to claim 6, characterized in that saiddeflector (12) is placed and extended in such a way not to cover eithersaid main holes (3) and said secondary holes (4).
 8. Atmospheric burneraccording to claim 1, characterized in that it is provided with atemperature sensor (9) lodged inside said second portion.
 9. Cookingoven comprising a cooking chamber and a gas burner contained orassociated to said cooking chamber, characterized in that said gasburner is carried out according to claim
 1. 10. Cooking oven accordingto claim 9, characterized in that it is provided with control means ableof allowing the gas selectively and independently flowing both to themain burner (1) and to the secondary burner (mini-burner) (6).